question about branch island

[Eric Fisher]

Hi,
I'm working on a gcc/binutils port and met with a problem. The target
doesn't have absolute address jump. So for function call, the linker
sometimes complains about "relocation truncated to fit". I used the
pc-relative branch to implement function call, but I think this is a
bug. They told me about branch island, which ppc used. I've got the
codes about branch island of gcc-3.4.4. But it seems that
binutils-2.14 doesn't implement it. Even failed when I try to build
with --target=ppc-darwin. The configuration said,
*** This configuration is not supported in the following subdirectories:
     bfd binutils ld gas opcodes
    (Any other directories should still work fine.)

So can anyone tell me where is the example about how to implement
branch island in gas and ld.

Or is there any other way to solve the problem?

Thank you very much.
Eric.